Crankshaft lapping machine



Oct. 7, 1941. H. s. INDGE 2,258,571

CRANKSHAFT LAPPING MACHINE Filed-Jan. 12, 1940 2 Sheets-Sheet l 10s I 0 is 133 HEREER 7- fif/vass F 4 I Oct. 7, 1941. I H. s. INDGE 2,258,571 CRANKSHAFT LAPPING MACHINE Filed Jan. 12, 1940 2 Sheets-Sheet 2 E Q g HEREER TEZNDEE mmwn lapping Patented Dot. 7, 1941 CRANKSHAFT LAPrrNG MACHINE Herbert S. Indge, Westboro Mass assignor to Norton Company, WcrcestenMass a corporation of Massachusetts Application January 12, 1940, Serial No. 313,590 3 Claims. (Cl. 5 1161) The invention relates to abrading machines,

and more particularly to a crankshaft lapping machine.

One object of the invention is to provide a "crank lapping machine which will more effec- 51 tively lap and finish a plurality of crankpins or hearings on an automobile crankshaft; A fur-- their object of the invention is to provide a crankshaft lapping machine in which a plurality of lapping elements are arranged to engage a pin or bearing to b lapped at spaced intervals.

Another object of the invention is to provide a crank lapping machine in which the crank lapping arm is provided with a plurality of independently spaced lapping elements which are,

yieldably maintained in engagement with the work piece to be lapped. A further object of the invention is to provide an improved crank lapping machine having a plurality of spaced, independent, pressure controlled lapping eleirints for engaging a work piece at spaced intervals above its periphery. A further object of the invention is to provide a lapping arm having a plurality of pneumatically controlled lapping elements for engaginglthe Work piece at a a plurality ofspaced positions at predetermined pressures. Other objects will be in part obvious or in part pointed out hereinafter. The invention accordingly consists in the features of construction, combinations of elements, i" and arrangements of parts, as will be exemplifid in the structure to be hereinafter described, and the scope of the applicationof which will be indicated in the following claims.

f y In the accompanying drawings in which is shown one of various possibl embodiments of the mechanical features of the invention,

Fig. 1 is a cross sectional view through the improved crankshaft lapping machine;

Fig. 2 is a fragmentary perspective view, on an F, enlarged scale, of the crank or bearing lapping arms and the actuating mechanism therefor;

Fig. 3 is a fragmentary detail view, partly-in section, showing the lapping head on the arm shown in Fig. 2;

Fig. 4 is a fragmentary constructional and diagrammatic view, showing the headstock controlling mechanism and the pneumatic pressure control for the lapping elements; and

Fig. 5 is. a fragmentary cross sectional view Q is.

through the air controlled valve for controlling the application of pneumatic pressure to the elements.

A crankshaft lapping machine has beenlillustrate'din the? drawings comprising a base l which supports a longitudinally reciprocable work supporting table ll Table ways are provided between the base ill and the table II which in th preferred form are of an anti-friction type; The base I!) is provided with a plate [3 which is fixedly mounted on thebase H) and is provided on its opposite edges with parallel V-shaped grooves l4 and I which serve as inner raceways for a pair of spaced rows of antifriction balls l6 and I1, respectively. A cage (not shown) is provided between the races to space the balls l6 and I1 longitudinally as desired. This construction forms an anti-friction way between the table I l and the base Ill whereby the table together with a headstock l8 and a footstock (not shown) may be readily reciprocated during the lapping operation.

The arrangement of the headstock and footstock and associated parts is substantially identical with that shown in my prior Patent No. 2,166,009 dated Julyll, 1939, to which reference may be had for details of disclosure not contained herein.

Lapping arm support It is desirable to provide a movable support for a plurality of crankpin and bearing lapping arms so that they may be simultaneously and rapidly moved into an operativ or inoperative position as desired. A pair of spaced supporting arms 20, only one of which has been illustrated in the drawings (Fig. 1), are mounted on a rock shaft 2! which is journalled in suitable bearings on the rear of the machine base Ill. The arms 26 are provided with horizontally extending portions which are connected by two spaced bars Hand 23 which serve as slide bars or ways for a slide which supports a plurality of lapping arms to be hereinafter described,

The lapping arm assembly supported by. the arms is arranged so that they may be automatically moved to and from an operative position to facilitate loading of crankshafts into the machine and removing them therefrom after a lapping operation has been completed. In order to move the entire lapping arm assembly to an inoperative position, a fluid pressure mechanism is provided comprising a fluid pressure cylinder 24 which is pivotally connected by means of a stud 25 with the base ID of the machine. A piston 2B is slidably mounted within the cylinder 24 and is connected to one end of a piston rod 21. The other end of the piston rod 21 is connected by a stud 28 with a rock arm 29 which is pivotally supported. on a shaft 30 within the base l8 of the machine. The arm 29 is provided with a stud 3| which is connected to one end of a link 32. The other end of the link 32 is connected by a stud 33 with the adjacent ends of a pair of toggle levers 34 and 35. The toggle lever 34 is connected at its other end by means of a stud 36 with the base In, and the toggle lever 35 is connected by a stud 31 with an arm 38 which is fixedly mounted on the rock shaft 2|. The assembly above described is arranged to rock the shaft 2| together with the arms 28 and all of the crankpin and bearing lapping arms together with their supporting and actuating mechanisms either into or away from an operative position. Levers 29, 32, 34 and 35, as shown in full lines in Fig. 1, are in an operative position to hold the arm 38 and the arms 28 together with the entire lapping arm assembly in an operative position. When a lapping operation has been completed, fluid under pressure is admitted to the cylinder 24 to cause the piston 28 and the piston rod 21 to move toward the right (Fig. 1) so as to shift the lever mechanism above described to rock the arm 38, the rock shaft 2|, together with the arms 28, in a clockwise direction (Fig. 1) to move the entire lapping arm assembly to an inoperative position.

A fluid pressure system is provided to control the admission of fluid under pressure to the cylinder 24. A motor driven fluid pressure pump 39 within the base H of the machine draws fluid through a pipe 40 from a reservoir 4| within the base l and passes fluid under pressure through a pipe 42 to a control valve 43. The valve 43 is of a balanced piston type having a valve stem 44 which is provided at its outer end with a spoolshaped member 45 and is connected to a control lever 4'! by means of a pair of diametrically opposed studs or pins 46 mounted on a yoked end of the control lever 47. The control lever 41 is pivotally supported on a stud 48 which is carried by a bracket 49 fixedly supported on the front of the base |8 of the machine. A plurality of valve pistons 52, 53and 54 are formed integral with the valve stem 44. Fluid under pressure passing through the pipe 42 enters a valve chamber 55 located between the valve pistons 53 and 54 and passes out through a pipe 55 into a cylinder chamber 51 to cause the piston 26 to move toward the left (Fig. 1) to shift the lapping arm supports 28 in a counterclockwise direction (Fig. 1) to position the crankpin and bearing lapping arms in an operative position. During the admission of fluid under pressure to the cylinder chamber 51, fluid is exhausted from a cylinder chamber 58 at the other end of the cylinder 24, through a pipe 59, a valve chamber 68 located between the valve pistons 52 and 53, and out through a pipe 6| which exhausts into the reservoir 4|. A fluid pressure relief valve 52 is connected by a pipe 53 with the pipe line 52 and serves to by-pass excess fluid under pressure if the pressure within the pipe line 42 for any reason increases over the desired and predetermined operating pressure.

After a lapping operation has been completed, the control lever 41 is rocked in a counterclockwise direction to shift the valve 43 into a reverse position so that fluid under pressure from the pump 39 passing through the pipe 42 enters the valve chamber 58 located between the valve pistons 52 and 53 andpasses out through the pipe 59 into the cylinder chamber 58. The admission of fluid under pressure to the cylinder chamber 58 causes the'piston 25 and the piston rod 2'! to move toward the right (Fig. 1), which movement serves through the lever mechanism above described to rock the arm 38, the rock shaft 2|, and the arms 28 so as to move the entire lapping arm assembly in a clockwise direction (Fig. 1) to an inoperative position with the lapping arms out of engagement with the crankshaft being lapped. During this movement, fluid within the cylinder chamber 5i exhausts through the pipe 58, through the valve chamber 55, and through the pipe 6! into the reservoir 4|.

H eadstock The headstock I8 is provided with a rotatable spindle 64 which is supported in suitable bearings within the headstock frame. The headstock is substantially identical to that shown in the prior patent to Indge and Hulbert No. 2,092,734 dated September '7, 1927, to which reference may be had for details of disclosure not contained herein. The headstock spindle may be rotated from any suitable source of power, such as an overhead belt drive or a self-contained electric motor. In the preferred construction, an electric motor 65 is mounted within the base I0 and is provided with a driving pulley 65 which is connected by a multiple V-belt 6'1 with a pulley 68 on the headstock |8. The pulley 88 is drivingly connected to rotate the headstock spindle 64 in a manner substantially the same as that shown in the above-mentioned U. S. Patent No. 2,092,734. A manually operable control lever 59 is provided to facilitate starting and stopping the headstock spindle 84 as desired to control the lapping cycle.

Lapping arm A plurality of crankpin and bearing lapping arms 18 are provided, one arm being provided for each crankpin and main bearing on the shaft to be finished. Each of the lapping arms 78 is pivotally supported on a stud 7| which is in turn supported on the upper end of an arm 12. The lapping arms 18 each carry on their forward ends a plurality of lapping elements l3, l4 and 15. The lapping elements l3, l4 and 15 are supported by a pair of pivotally mounted lap supporting arms 18 and 11. The arms 75 and l? are pivotally supported by studs 18 and 19, respectively, on the lapping arm 78. The other ends of the arms 16 and T! are connected by a pair of toggle levers 88 and 8| which are connected together at their inner ends by means of a stud 82 which slides within elongated slots 83 (Fig. 2) formed in the side plates of the lapping arm 10. When the toggle levers and 8| are in a straight line position (Figs. 1 and 2), the lap supporting arms 18 and 11 are maintained in an operative position with the lapping elements 73, 14 and 15 in operatwo contact with the crankpin or hearing to be lapped. In the preferred construction, the lapping arms 18 are arranged to be automatically actuated to shift the lapping elements into and away from an operative position in engagement with the work piece to be lapped.

A fluid pressure mechanism is provided for actuating the toggle levers 88 and 8|, comprising a cylinder 84 having a piston 85 slidably mounted therein. The piston 85 is connected to one end of a piston rod 86. The other end of the piston rod 86 is provided with a block 81 which is connected by means of a stud 88 with a link 89, the other end of which is connected to the stud 82. When fluid under pressure is admitted through a pipe 98 into a cylinder chamber 9| to move the piston 85 toward the right into the position illustrated in Fig, 2, the

aatazsvi toggle levers .80 and BI are moved into a straight-- line position to locate the lapping elements 13, Hand 15 in operative engagement with a work piece. During this movementfl-uid is exhausted from a cylinder chamber 92 through a pipe 93.

Similarly, when fluid under pressure is admitted through the pipe 93 into the cylinder chamber 92, the piston 85, piston'rod 86, and the link 89 are moved toward the left (Fig. 2) which serves to shift the toggle levers B'and 8I from the full line positions (Fig. 2) which serves to rock the lap supporting arms I6and TI to move the lapping elements I3; 14 and I5 to an inoperative position. Pipes 9'0 and 93 are preferably flexible pipes or tubes to facilitate a swinging movement of the arms I0 during a lapping operation. The pipes 90 and M are connected to a pair ofmanifolds or pipes 9'4 and 95, respectively, which extend longitudinally between the arms at the rear of the machine to provide a readily accessible means whereby any number of lapping arms I0 may be provided on the machine.

It is desirable that the lapping arm I0 be so arranged that the arms for lapping or finishing a crankpin may readily follow the movement of the 'crankpin during its revolution. As illustrated in the drawings, a lower crankpin or bearing engaging shoe I05 is provided having a partial internal cylindrical surface which is arranged to mate with and engage the lower portion of a workpiece, such as a crankpin or main bearing. Similarly, anupper crankpin or bearing engaging shoe I06 is provided, having a partial internal cylindrical surface for engaging the upper surface of the'work. The shoes I05 and I06 are U to movement of the'work piece, thus leavingthe abrading or lapping elements to perform only their abrading or lapping operation.

The shoes I05 and I00 may be locked in a rigid operating position on the work by means of the toggle levers 80 and 8|; In order to facilitate alignment of the shoes 05 and I06 with the periphery of the crankpin or main bear-- ing as they are moved into an operating position. a floating. connection is preferably provided between said shoes and the arms TI and .16; respec-- tively.

To facilitate an independent regulation of the pressure of the lapping elements on the surface of the work being lapped or finished; a fluid pressure mechanism is provided; comprising. fluid pressure cylinders I01, I09 and I09 which extend radially with respect to the lapping elements I3, .14 and I5, as well as radially relative to the crank or bearing to be lapped. Each of the cylinder's VI 0?, I08 and I09 contains a slidably mounted piston H9 which is connected by means of a piston rod III with the lapping elements I3, i l and I5, respectively. Fluid under pressure, such as pneumatic pressure, is supplied through a pipe Il2 into the cylinder chamber above the piston I I9 to exert a pressure on the lapping element 73. Similarly, pressure may be simultaneously admitted through pipes H3 and I I4 to the cylinders lflflzand I99, respectively, .to apply a :definite and predetermined pressureto. the lapping elements "Hand .15. respectively; to 'maintain the lappingelernents inoperative lapping engagement with the work piece. ,It'cwill-be' readily apparent from the foregoing that thethrust of the crankpin on the lappingarm T0 istaken entirelyby the shoes I05 and I06, respectively. I i

A spring H5 surrounds, each of the piston rods III and is." interposed between the piston H0 andithemembers I051' and .I06, respectively, and serve to maintain the lapping elements in an inoperative position. The cylinders 10! and I09 are fixedly supported by the shoe I06 and the cylinder I99 islfixedly supported on'tlieshoe I05. The cylinder :I09 passes through aclearance aperture H6 (Fig. 3) formed in the lap supporting arm I! and servesto provide a float ing movement .of the shoe I05. as the lap supporting arms l6-and N are moved into an operative position. The cylinder I08 passes'through a clearance, aperture, H1. in the lap supporting arm 16; The shoe-I06 together with the cylin ders I91, and 108 supported thereby are carried by a stud II8 which is adjustably, mounted, for adjustment in a vertical directicnxby means of a screw adjusting mechanism II9,thus forming itselfaligning, supportfor'the member I06 so that-whenthe lap supporting arms I5 and H are moved into anoperative position, the shoe I06 may readily align itself with the crankpin or hearing surface to be finished. ltwill' be readily apparent fromthe foregoing disclosure that the abrading or lapping elements 13;"14 and lli are arranged so that they donot take any of the thrust of the: crank or the movement of the lapping arm but are independently controlled and 1 serve only as lapping elements to .lap. and finish the predetermined portions of the work piece.

In order to supply'fluid underpressure, such ascompresse'd 2.113170 apply the desired lapping pressure to the elements", "and I5, .2. suitable compressed air apparatus may be provided. Connection may be made to the standard compressed air line which passes through most modern manufacturing plants or, if desired, a compressed air unit may be provided either adjacent to or within the base of the machine, comprising an air compressor I (shown diagrammatically in Fig. 4). Air is forced under pressure by the compressor I25 into a compression tank or chamber I26 which is connected by means of a pipe I21 and a pressure control valve I28 to a pipe I29 which connects with the pipes H2, H3 and I I4 simultaneously and uniformly to apply equal and predetermined pressures to the lapping elements 13, I4 and 15, thus producing a uniform lapping or abrading action by each of the lapping elements.

To facilitate automatic operation of the pressure control device, a control valve I30 is mounted in the pipe line I29. The valve I30 is arranged to be actuated by means of a roller I3I supported at the lower end of the headstock control lever 69 so that when the control lever 69 is moved into the full line position (Fig. 4) to start rotation of the work at the beginning of a lapping cycle, the roller I3I acting upon a cam face at the upper end of the valve I30, will depress the valve into the position illustrated in Fig. 4 to admit fluid under pressure through the pipe I29 to! apply the desired operating pressures to the lapping elements 13, I4 and I5. The valve I30 is normally held in an up position by means of a spring I33 in which position the fluid or compressed air Within the pipe I29 is cut ofi so that the released compression of the springs II5 will maintain the lapping elements I3, I4 and I5 out of operative lapping engagement with the pin or bearing being finished.

Fluid under pressure from the pump 39 within the base ID of the machine passes through the pipe 42 and through a pipe I36 to a manually operable control valve I35. The valve I35 is preferably a rotary type valve having a valve rotor I34 rotatably supported within the valve casing. Fluid under pressure passing through the pipe I36 passes through a valve chamber I31 formed in the valve rotor I 34 and is forced out through a pipe I38 which connects with a pipe or manifold 95 extending longitudinally of the machine. The manifold 95 is connected by means of flexible pipes with the hydraulic actuating mechanism for the lapping arms I9 (only one of the pipes and arms having been illustrated in the present case) Fluid under pressure within the manifold 95 passes through a flexible pipe or conduit 99, into a cylinder chamber 9|, to move the piston 85 upwardly into the position shown in Fig. 1.

During this movement, fluid within a cylinder chamber 92 exhausts through a flexible pipe 93 into a pipe or manifold 94 which extends longitudinally of the machine. Fluid exhausts from the manifold 94, through a pipe I39, a valve chamber I40 formed in the valve rotor I34, and passes out through a pipe I4I which exhausts into the reservoir 4 I. It will be readily apparent that in the position of the valve I35 as illustrated in Fig. l, the lapping elements and supporting arms I6 and II will be moved into an operative position. When the valve rotor I34 is rotated one-quarter turn, the direction of flow of fluid under pressure will be reversed to cause the piston 85 to move downwardly toward the left (Fig. 1) to remove the supporting arms I6 and 11 into an inoperative position.

The operation of this improved crankshaft lapping machine will be readily apparent from the foregoing disclosure. A crankshaft to be lapped is placed in position on the work supporting centers of the headstock I8 and footstock (not shown). The lever 4I is then moved into the position illustrated in Fig. 1 to swing the lapping arm assembly supported by the arms 29 in a counterclockwise direction to move the lapping arm i6 into an operative position. The'valve rotor I34 is then shifted into the position illustrated in Fig. 1 to admit fluid under pressure to the cylinder chamber 9| to actuate the toggle levers 89 and 8|, respectively, to swing the lap engaging members I65 and I66, respectively, into operative engagement with the pin or bearing to be lapped. At the same time, the headstock control lever 69 is moved in a counterclockwise direction to start the rotation of the crankshaft to be lapped and at the same time to actuate the air controlled valve I30 to apply a definite and predetermined lapping pressure to the lapping elements I3, 14 and I5. The lapping operation may then proceed to the desiredextent, after which the headstock lever 69 is again moved either manually or automatically to stop rotation of the work piece and the valve rotor I34 of the valve I35 is rotated to reverse the direction of flow of fluid under pressure to actuate the toggle levers and BI, respectively, to swing the lap supporting arms I6 and 11 so as to remove the elements or members I and I56 from operative engagement with the work. In this position of the parts, the main control lever 41 may then be moved in a counterclockwise direction (Fig. 1) to admit fluid under pressure to the cylinder chamber 58 to cause the lapping arm assembly to be rocked to an inoperative position to facilitate removal of the finished camshaft and the insertion of a new shaft to be lapped.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a crankshaft lapping machine having a movable crankpin lapping arm, a pair of opposed crankpin engaging shoes, means to move said shoes into and out of engagement with a crankpin to be lapped, said shoes being arranged to take up the thrust of said lapping arm, a plurality of lapping elements movably supported by said shoes, and means to apply a uniform predetermined pressure to all of said lapping elements.

2. In a crankshaft lapping machine having a pivotally supported crankpin lapping arm, a pair of opposed crankpin engaging shoes whereby the arm is moved with the crankpin during rotation thereof, a plurality of radially movable lapping elements supported by said shoes, and means including a piston and cylinder supported on said shoes for independently moving each of said elements into operative engagement with a crankpin and maintaining them in operative contact at a uniform predetermined pressure during the lapping operation.

3. In a crankshaft lapping machine having a movable crankpin lapping arm, a pair of opposed crankpin engaging shoes, means to move said shoes into and out of an operative position, said shoes being arranged to take up the thrust of the lapping arm, a plurality of fluid pressure cylinders supported on said shoes, pistons in said cylinders, a plurality of lapping elements actuated by said pistons and arranged to be moved in a substantially radial direction into engagement with a work piece to be lapped, and means simultaneously to admit fluid under pressure to all of said cylinders to move and maintain said lapping elements in lapping engagement with the work piece at a predetermined pressure.

HERBERT S. IN'DGE. 

